Owing to developments in image and sound processing technology, a large quantity of high image and sound quality content has been produced. Users who demand high image and sound quality content want realistic images and sound, and thus research into stereoscopic image and stereophonic sound has been actively conducted.
A stereophonic sound indicates a sound that gives a sense of ambience by reproducing not only a pitch and a tone of the sound but also a three-dimensional (3D) direction including horizontal and vertical directions and a sense of distance, and having additional spatial information by which an audience, who is not located in a space where a sound source is generated, is made aware of a sense of direction, a sense of distance, and a sense of space.
When a multi-channel signal, such as 22.2 channel signal, is rendered as a 5.1 channel signal by using a virtual rendering technology, a 3D stereophonic sound can be reproduced by means of a two-dimensional (2D) output channel.